A Russian amateur astronomer, Leonid Elenin of
Lyubertsy near Moscow, discovered a 19th magnitude comet
on December 10, 2010, using a remotely controlled
telescope situated in New Mexico, USA.

The comet will pass perihelion on September
10, 2011 at a distance of 0.48 AU, later encountering
the Earth on October 17 at 0.23 AU.

The observing circumstances from Earth's perspective are
highly favourable as comets are concerned. The close
passage to the Sun and later close encounter with Earth
are important factors in producing bright comets,
especially if the solar encounter causes disruption to the
nucleus, releasing dust particles.

Unfortunately the comet appears intrinsically faint
(absolute magnitude 10). Intrinsically faint comets are
usually gas rich and dust poor, but they do have a
tendency to brighten rapidly at perihelion.

The comet is inclined only 1.8 degrees from Earths
orbit thus we will observe the comet virtually edge-on
throughout the apparition. This will enhance the dust tail
and trail - should the comet actually be able to produce
dust!

The comet may appear visible to the unaided
eye at magnitude 4, when well situated in the evening
sky for Southern hemisphere observers during early
September 2011.

By mid September, it continues to brighten but is lost
to evening twilight.

By late September, it passes 2 degrees from the Sun
and should be visible through the SOHO C3 coronagraph
(between Sep 23 and 29), and STEREO A&B spacecraft.

A maximum phase angle of 177 degrees is
reached around September 26. Dust is very efficient at
forward scattering of sunlight.

A surge of 2 magnitudes is possible if the comet is
dust rich. However, the comet is not expected to be
observable from the ground, and any attempts to do so will
be very risky!

During early October, comet Elenin reappears
in dawn skies for Northern hemisphere observers.

Southerners need to wait until mid-October
before the comet is sufficiently high enough for
observation, but moonlight
will interfere until October 23rd.